1. Field of the Invention
The present invention relates to solar heating devices, and more particularly to solar heat exchangers of the passive kind.
2. Description of the Prior Art
With the recent public interest in conserving energy and with the resulting attention to recovery of solar heat, various solar panels were developed in the recent past for collecting solar heat by heat exchange with fluid. Most frequently the solar panels of the previous kinds were of the tubular construction, each of the tubes being exposed to the sky in order to receive solar radiation. Heretofor the primary concern in heat exchangers of this kind was the cost of production thereof. While solar power is virtually inexhaustable, in commercial applications, stringent limitations exist in the amortized cost factor since it is this cost factor that must be traded off against the present cost of fuel. Both because of the relatively high cost of present manufacture and the low thermal efficiency of the more economical panels, full acceptance of solar heating has yet not occurred.
Low efficiency most frequently occurs because of reflective losses, the panel surfaces never achieving the full absorption factors of a black body and the greenhouse effect always allowing some of the heat to be radiated back out. Accordingly, each effort to reduce cost is accompanied by lower efficiency levels which in turn raises the cost per btu produced. For these reasons, inexpensive techniques for capturing solar energy are not vigorously sought and it is to this purpose that the present invention is directed.